Tissue extraction devices and methods

ABSTRACT

Tissue may be cut and extracted from an interior location in a patient&#39;s body using a probe or tool which both effects cutting and causes vaporization of a liquid or other fluid to propel the cut tissue through an extraction lumen of the cutting device. The cutting may be achieved using an electrosurgical electrode assembly, including a first electrode on a cutting member and a second electrode within a cutting probe or tool.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/664,177, filed Oct. 30, 2012, now U.S. Pat. No. 9,597,149, issuedMar. 21, 2017, which claims the benefit of U.S. Provisional ApplicationNo. 61/555,655, filed Nov. 4, 2011, the full disclosures of which areincorporated herein by reference.

The specification of this application includes FIGS. 1-24 and theassociated text from non-provisional application Ser. No. 13/277,913,the full disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates systems and methods for the cutting andextraction of uterine fibroid tissue, polyps and other abnormal uterinetissue.

BACKGROUND OF THE INVENTION

Uterine fibroids are non-cancerous tumors that develop in the wall ofuterus. Such fibroids occur in a large percentage of the femalepopulation, with some studies indicating that up to 40 percent of allwomen have fibroids. Uterine fibroids can grow over time to be severalcentimeters in diameter and symptoms can include menorrhagia,reproductive dysfunction, pelvic pressure and pain.

One current treatment of fibroids is hysteroscopic resection ormyomectomy which involves transcervical access to the uterus with ahysteroscope together with insertion of a cutting instrument through aworking channel in the hysteroscope. The cutting instrument may be amechanical tissue cutter or an electrosurgical resection device such asa cutting loop. Mechanical cutting devices are disclosed in U.S. Pat.Nos. 7,226,459; 6,032,673 and 5,730,752 and U.S. Published PatentApplication 2009/0270898. An electrosurgical cutting device is disclosedin U.S. Pat. No. 5,906,615.

While hysteroscopic resection can be effective in removing uterinefibroids, many commercially available instrument are too large indiameter and thus require anesthesia in an operating room environment.Conventional resectoscopes require cervical dilation to about 9 mm. Whatis needed is a system that can effectively cut and remove fibroid tissuethrough a small diameter hysteroscope.

SUMMARY OF THE INVENTION

The present invention provides methods for resecting and removing targettissue from a patient's body, such as fibroids from a uterus. The tissueis cut, captured in a probe, catheter, or other tissue-removal device,and expelled from the capture device by vaporizing a fluid, typically aliquid, adjacent to the captured tissue in order to propel the tissuefrom the device, typically through an extraction or other lumen presentin a body or shaft of the device. Exemplary embodiments, the tissueremoval device comprise a reciprocating blade, tubular cutter, or thelike, where the blade may be advanced past a cutting window on thedevice in order to sever a tissue strip and capture the strip within aninterior volume or receptacle on the device. The liquid or otherexpandable fluid is also present in the device, and energy is applied tothe fluid in order to cause rapid expansion, e.g. vaporization, in orderto propel the severed tissue strip through the extraction lumen. In thisway, the dimensions of the extraction lumen can be reduced, particularlyin the distal regions of the device where size is of criticalimportance.

In a first method, according to the present invention, tissue isextracted from an interior of the patient's body by capturing a tissuevolume in a distal portion of an interior passageway of an elongatedprobe. A fluid located distal to the captured tissue volume is expandedwhich proximally propels the tissue volume from the device. The fluidtypically comprises a liquid, and the expansion typically comprises aliquid-to-vapor phase transition. In other cases, the fluid might be agas where the expansion results from very rapid heating. In preferredembodiments, the phase transition is achieved by applying electricalenergy in an amount sufficient to vaporize the liquid, typicallyapplying RF current between first and second polarity electrodes, whereat least one of the electrodes is disposed on a distal side of thecaptured tissue volume.

The liquid or other fluid may be provided to a working end of the probein various ways. Often, the liquid or other fluid is provided from afluid-filled space in the patient's body, for example from a distensionfluid filled in the cavity to be treated, such as the uterus.Alternatively, the liquid or other fluid may be provided from a remotesource through a passageway in the probe. The liquid volume to bevaporized is typically in the range from 0.004 mL to 0.080 mL.

The tissue may be captured in a variety of ways. For example, the tissuemay be resected with a blade number or alternatively with an RFelectrode. In either case, the resected tissue may then be captured orsequestered within an interior passageway within the blade itself and/orwithin another portion of the probe. In addition to the propulsion forcecaused by the vaporizing fluid, the present invention might also rely onapplying a negative pressure to a proximal end of the anteriorpassageway to assist in drawing the tissue in a proximal direction fromthe extraction lumen.

In a further method according to the present invention, tissue isremoved from the interior of a patient's body by engaging a tubularcutter against the targeted tissue. An RF electrode arrangement on thecutter is energized to electrosurgically cut the tissue, and the same ora different RF electrode is used to vaporize a liquid to apply apositive fluid pressure to a distal surface of the cut tissue. Usually,the same RF electrode arrangement is used to both electrosurgically cutthe tissue and to vaporize the liquid. In such instances, the cuttercarrying the RF electrode is usually first advanced to electrosurgicallycut the tissue and thereafter advanced into the liquid to vaporize theliquid. The liquid is usually present in a chamber or other space havingan active electrode at a distal end thereof, and the RF electrodearrangement on the cutter comprises a return electrode. In this way,with the smaller active electrode on the distal side of the tissue, theenergy which vaporizes the liquid will be concentrated in the chamber onthe distal side of the tissue, thus causing rapid vaporization of theliquid and propulsion of the tissue through the extraction lumen.

In a third method according to the present invention, tissue is cut andextracted from the interior of a patient's body by reciprocating acutting member within a tubular cutter body to sever a tissue strip. Thesevered tissue strip is captured in an extraction lumen of the tubularcutter body, and a phase transition is caused in a fluid distal to thetissue strip to thereby apply a proximally directed expelling orpropulsion force to the tissue strip. The phase transition may be causedby applying energy from any one of a variety of energy sources,including an ultrasound transducer, a high-intensity focused ultrasound(HIFU) energy source, a laser energy source, a light or optical energysource, a microwave energy source, a resistive heat source, or the like.Typically, the cutter will carry the energy source, and the energysource is also used to effect cutting of the tissue. In this way thecutter can also carry the energy source into the fluid after the tissuehas been cut, and the cutting and vaporization steps can be performedsequentially as the cutter first moves through the tissue and then intothe liquid or other fluid to be vaporized.

In a still further method according to the present invention, tissue iscut and extracted by first cutting the tissue with a reciprocatingcutting member over an extending stroke and a retracting stroke within asleeve. The extending stroke cuts and captures tissue which has beendrawn through a tissue-receiving window in the sleeve. Vaporization of aliquid distal to the captured tissue is caused by the cutting memberwhile the cutting member is in a transition range between extension andretraction. The tissue is typically captured in the tissue extractionlumen formed at least partially in the cutter member. The cutter membertypically carries a cutting electrode, and a second electrode istypically disposed at a distal end of the sleeve. Thus, RF current maybe delivered to the cutting electrode and the second electrode in orderto both effect cutting of the tissue over the extending stroke of thecutter and to also effect vaporization of the fluid while the cutter isin the transition range.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of an assembly including a hysteroscope and atissue-cutting device corresponding to the invention that is insertedthrough a working channel of the hysteroscope.

FIG. 2 is a schematic perspective view of a fluid management system usedfor distending the uterus and for assisting in electrosurgical tissuecutting and extraction.

FIG. 3 is a cross-sectional view of the shaft of the hysteroscope ofFIG. 1 showing various channels therein.

FIG. 4 is a schematic side view of the working end of theelectrosurgical tissue-cutting device of FIG. 1 showing an outer sleeveand a reciprocating inner sleeve and an electrode arrangement.

FIG. 5 is a schematic perspective view of the working end of the innersleeve of FIG. 4 showing its electrode edge.

FIG. 6A is a schematic cut-away view of a portion of outer sleeve, innerRF cutting sleeve and a tissue-receiving window of the outer sleeve.

FIG. 6B is a schematic view of a distal end portion another embodimentof inner RF cutting sleeve.

FIG. 7A is a cross sectional view of the inner RF cutting sleeve of FIG.6B taken along line 7A-7A of FIG. 6B.

FIG. 7B is another cross sectional view of the inner RF cutting sleeveof FIG. 6B taken along line 7B-7B of FIG. 6B.

FIG. 8 is a schematic view of a distal end portion of another embodimentof inner RF cutting sleeve.

FIG. 9A is a cross sectional view of the RF cutting sleeve of FIG. 8taken along line 9A-9A of FIG. 8.

FIG. 9B is a cross sectional view of the RF cutting sleeve of FIG. 8taken along line 9B-9B of FIG. 8.

FIG. 10A is a perspective view of the working end of the tissue-cuttingdevice of FIG. 1 with the reciprocating RF cutting sleeve in anon-extended position.

FIG. 10B is a perspective view of the tissue-cutting device of FIG. 1with the reciprocating RF cutting sleeve in a partially extendedposition.

FIG. 10C is a perspective view of the tissue-cutting device of FIG. 1with the reciprocating RF cutting sleeve in a fully extended positionacross the tissue-receiving window.

FIG. 11A is a sectional view of the working end of the tissue-cuttingdevice of FIG. 10A with the reciprocating RF cutting sleeve in anon-extended position.

FIG. 11B is a sectional view of the working end of FIG. 10B with thereciprocating RF cutting sleeve in a partially extended position.

FIG. 11C is a sectional view of the working end of FIG. 10C with thereciprocating RF cutting sleeve in a fully extended position.

FIG. 12A is an enlarged sectional view of the working end oftissue-cutting device of FIG. 11B with the reciprocating RF cuttingsleeve in a partially extended position showing the RF field in a firstRF mode and plasma cutting of tissue.

FIG. 12B is an enlarged sectional view of the working end of FIG. 11Cwith the reciprocating RF cutting sleeve almost fully extended andshowing the RF fields switching to a second RF mode from a first RF modeshown in FIG. 12.

FIG. 12C is an enlarged sectional view of the working end of FIG. 11Cwith the reciprocating RF cutting sleeve again almost fully extended andshowing the explosive vaporization of a captured liquid volume to expelcut tissue in the proximal direction.

FIG. 13 is an enlarged perspective view of a portion of the working endof FIG. 12C showing an interior chamber and a fluted projecting element.

FIG. 14 is a sectional view of the working end of FIG. 12C showing aninterior chamber and a variation of a projecting element.

FIG. 15 is a sectional view of the working end of FIG. 12C showing aninterior chamber and a variation of a projecting element configured toexplosively vaporize the captured liquid volume.

FIG. 16A is a perspective view of an alternative working end with arotational cutter in a window open position.

FIG. 16B is a perspective view of the working end of FIG. 16A with therotating cutting element in a second position.

FIG. 16C is a view of the working end of FIGS. 16A-16B with the rotatingcutting element in a third position.

FIG. 17 is an exploded view of the outer sleeve of the working end ofFIGS. 16A-16C showing the mating components comprising a ceramic bodyand a metal tube.

FIG. 18 is a view of the inner sleeve of the working end of FIGS.16A-16C de-mated from the outer sleeve.

FIG. 19 is an exploded view of the inner sleeve of FIG. 18 showing themating components comprising a ceramic body and a metal tube.

FIG. 20A is a cross sectional view of the working end of FIGS. 16A-16Cwith the rotating inner sleeve in a first position cutting tissue in afirst RF mode.

FIG. 20B is a cross sectional view of the working end of FIG. 20A withthe rotating inner sleeve in a second window-closed position with asecond RF mode vaporizing saline captured in the interior extractionchannel.

FIG. 21 is a longitudinal sectional view corresponding to the view ofFIG. 20B with the rotating inner sleeve in a window-closed position andwith the second RF mode vaporizing saline captured in the interiorextraction channel to expel tissue proximally.

FIG. 22 is a view of an alternative embodiment of a metal tube componentof an inner sleeve.

FIG. 23 is a view of an alternative embodiment of a metal tube componentof an inner sleeve.

FIG. 24 is a perspective view of an alternative probe that is configuredto stop the inner rotating sleeve in a particular position.

FIG. 25 is a schematic view of another fluid management systemcorresponding to the invention.

FIG. 26 is a diagram showing various pump and filter components of thefluid management system of FIG. 25.

FIG. 27 is a sectional view of an RF probe that is configured to stopthe inner rotating sleeve in a particular position to coagulate tissue.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an assembly that comprises an endoscope 50 used forhysteroscopy together with a tissue-extraction device 100 extendingthrough a working channel 102 of the endoscope. The endoscope orhysteroscope 50 has a handle 104 coupled to an elongated shaft 105having a diameter of 5 mm to 7 mm. The working channel 102 therein maybe round, D-shaped or any other suitable shape. The endoscope shaft 105is further configured with an optics channel 106 and one or more fluidinflow/outflow channels 108 a, 108 b (FIG. 3) that communicate withvalve-connectors 110 a, 110 b configured for coupling to a fluid inflowsource 120 thereto, or optionally a negative pressure source 125 (FIGS.1-2). The fluid inflow source 120 is a component of a fluid managementsystem 126 as is known in the art (FIG. 2) which comprises a fluidcontainer 128 and pump mechanism 130 which pumps fluid through thehysteroscope 50 into the uterine cavity. As can be seen in FIG. 2, thefluid management system 126 further includes the negative pressuresource 125 (which can comprise an operating room wall suction source)coupled to the tissue-cutting device 100. The handle 104 of theendoscope includes the angled extension portion 132 with optics to whicha videoscopic camera 135 can be operatively coupled. A light source 136also is coupled to light coupling 138 on the handle of the hysteroscope50. The working channel 102 of the hysteroscope is configured forinsertion and manipulation of the tissue-cutting and extracting device100, for example to treat and remove fibroid tissue. In one embodiment,the hysteroscope shaft 105 has an axial length of 21 cm, and cancomprise a 0° scope, or 15° to 30° scope.

Still referring to FIG. 1, the tissue-cutting device 100 has a highlyelongated shaft assembly 140 configured to extend through the workingchannel 102 in the hysteroscope. A handle 142 of the tissue-cuttingdevice 100 is adapted for manipulating the electrosurgical working end145 of the device. In use, the handle 142 can be manipulated bothrotationally and axially, for example, to orient the working end 145 tocut targeted fibroid tissue. The tissue-cutting device 100 hassubsystems coupled to its handle 142 to enable electrosurgical cuttingof targeted tissue. A radio frequency generator or RF source 150 andcontroller 155 are coupled to at least one RF electrode carried by theworking end 145 as will be described in detail below. In one embodimentshown in FIG. 1, an electrical cable 156 and negative pressure source125 are operatively coupled to a connector 158 in handle 142. Theelectrical cable couples the RF source 150 to the electrosurgicalworking end 145. The negative pressure source 125 communicates with atissue-extraction channel 160 in the shaft assembly 140 of the tissueextraction device 100 (FIG. 4).

FIG. 1 further illustrates a seal housing 162 that carries a flexibleseal 164 carried by the hysteroscope handle 104 for sealing the shaft140 of the tissue-cutting device 100 in the working channel 102 toprevent distending fluid from escaping from a uterine cavity.

In one embodiment as shown in FIG. 1, the handle 142 of tissue-cuttingdevice 100 includes a motor drive 165 for reciprocating or otherwisemoving a cutting component of the electrosurgical working end 145 aswill be described below. The handle 142 optionally includes one or moreactuator buttons 166 for actuating the device. In another embodiment, afootswitch can be used to operate the device. In one embodiment, thesystem includes a switch or control mechanism to provide a plurality ofreciprocation speeds, for example 1 Hz, 2 Hz, 3 Hz, 4 Hz and up to 8 Hz.Further, the system can include a mechanism for moving and locking thereciprocating cutting sleeve in a non-extended position and in anextended position. Further, the system can include a mechanism foractuating a single reciprocating stroke.

Referring to FIGS. 1 and 4, an electrosurgical tissue-cutting device hasan elongate shaft assembly 140 extending about longitudinal axis 168comprising an exterior or first outer sleeve 170 with passageway orlumen 172 therein that accommodates a second or inner sleeve 175 thatcan reciprocate (and optionally rotate or oscillate) in lumen 172 to cuttissue as is known in that art of such tubular cutters. In oneembodiment, the tissue-receiving window 176 in the outer sleeve 170 hasan axial length ranging between 10 mm and 30 mm and extends in a radialangle about outer sleeve 170 from about 45° to 210° relative to axis 168of the sleeve. The outer and inner sleeves 170 and 175 can comprise athin-wall stainless steel material and function as opposing polarityelectrodes as will be described in detail below. FIGS. 6A-8 illustrateinsulative layers carried by the outer and inner sleeves 170 and 175 tolimits, control and/or prevent unwanted electrical current flows betweencertain portions go the sleeve. In one embodiment, a stainless steelouter sleeve 170 has an O.D. of 0.143″ with an I.D. of 0.133″ and withan inner insulative layer (described below) the sleeve has a nominalI.D. of 0.125″. In this embodiment, the stainless steel inner sleeve 175has an O.D. of 0.120″ with an I.D. of 0.112″. The inner sleeve 175 withan outer insulative layer has a nominal O.D. of about 0.123″ to 0.124″to reciprocate in lumen 172. In other embodiments, outer and or innersleeves can be fabricated of metal, plastic, ceramic of a combinationthereof. The cross-section of the sleeves can be round, oval or anyother suitable shape.

As can be seen in FIG. 4, the distal end 177 of inner sleeve 175comprises a first polarity electrode with distal cutting electrode edge180 about which plasma can be generated. The electrode edge 180 also canbe described as an active electrode during tissue cutting since theelectrode edge 180 then has a substantially smaller surface area thanthe opposing polarity or return electrode. In one embodiment in FIG. 4,the exposed surfaces of outer sleeve 170 comprises the second polarityelectrode 185, which thus can be described as the return electrode sinceduring use such an electrode surface has a substantially larger surfacearea compared to the functionally exposed surface area of the activeelectrode edge 180.

In one aspect of the invention, the inner sleeve or cutting sleeve 175has an interior tissue extraction lumen 160 with first and secondinterior diameters that are adapted to electrosurgically cut tissuevolumes rapidly—and thereafter consistently extract the cut tissuestrips through the highly elongated lumen 160 without clogging. Nowreferring to FIGS. 5 and 6A, it can be seen that the inner sleeve 175has a first diameter portion 190A that extends from the handle 142(FIG. 1) to a distal region 192 of the sleeve 175 wherein the tissueextraction lumen transitions to a smaller second diameter lumen 190Bwith a reduced diameter indicated at B which is defined by the electrodesleeve element 195 that provides cutting electrode edge 180. The axiallength C of the reduced cross-section lumen 190B can range from about 2mm to 20 mm. In one embodiment, the first diameter A is 0.112″ and thesecond reduced diameter B is 0.100″. As shown in FIG. 5, the innersleeve 175 can be an electrically conductive stainless steel and thereduced diameter electrode portion also can comprise a stainless steelelectrode sleeve element 195 that is welded in place by weld 196 (FIG.6A). In another alternative embodiment, the electrode and reduceddiameter electrode sleeve element 195 comprises a tungsten tube that canbe press fit into the distal end 198 of inner sleeve 175. FIGS. 5 and 6Afurther illustrates the interfacing insulation layers 202 and 204carried by the first and second sleeves 170, 175, respectively. In FIG.6A, the outer sleeve 170 is lined with a thin-wall insulative material200, such as PFA, or another material described below. Similarly, theinner sleeve 175 has an exterior insulative layer 202. These coatingmaterials can be lubricious as well as electrically insulative to reducefriction during reciprocation of the inner sleeve 175.

The insulative layers 200 and 202 described above can comprise alubricious, hydrophobic or hydrophilic polymeric material. For example,the material can comprise a bio-compatible material such as PFA,TEFLON®, polytetrafluroethylene (PTFE), FEP (Fluorinatedethylenepropylene), polyethylene, polyamide, ECTFE(Ethylenechlorotrifluoro-ethylene), ETFE, PVDF, polyvinyl chloride orsilicone.

Now turning to FIG. 6B, another variation of inner sleeve 175 isillustrated in a schematic view together with a tissue volume beingresected with the plasma electrode edge 180. In this embodiment, as inother embodiments in this disclosure, the RF source operates at selectedoperational parameters to create a plasma around the electrode edge 180of electrode sleeve 195 as is known in the art. Thus, the plasmagenerated at electrode edge 180 can cut and ablate a path P in thetissue 220, and is suited for cutting fibroid tissue and other abnormaluterine tissue. In FIG. 6B, the distal portion of the cutting sleeve 175includes a ceramic collar 222 which is adjacent the distal edge 180 ofthe electrode sleeve 195. The ceramic 222 collar functions to confineplasma formation about the distal electrode edge 180 and functionsfurther to prevent plasma from contacting and damaging the polymerinsulative layer 202 on the cutting sleeve 175 during operation. In oneaspect of the invention, the path P cut in the tissue 220 with theplasma at electrode edge 180 provides a path P having an ablated widthindicated at W, wherein such path width W is substantially wide due totissue vaporization. This removal and vaporization of tissue in path Pis substantially different than the effect of cutting similar tissuewith a sharp blade edge, as in various prior art devices. A sharp bladeedge can divide tissue (without cauterization) but applies mechanicalforce to the tissue and may prevent a large cross section slug of tissuefrom being cut. In contrast, the plasma at the electrode edge 180 canvaporize a path P in tissue without applying any substantial force onthe tissue to thus cut larger cross sections or slugs strips of tissue.Further, the plasma cutting effect reduces the cross section of tissuestrip 225 received in the tissue-extraction lumen 190B. FIG. 6B depictsa tissue strip to 225 entering lumen 190B which has such a smallercross-section than the lumen due to the vaporization of tissue. Further,the cross section of tissue 225 as it enters the larger cross-sectionlumen 190A results in even greater free space 196 around the tissuestrip 225. Thus, the resection of tissue with the plasma electrode edge180, together with the lumen transition from the smaller cross-section(190B) to the larger cross-section (190A) of the tissue-extraction lumen160 can significantly reduce or eliminate the potential for successiveresected tissue strips 225 to clog the lumen. Prior art resectiondevices with such small diameter tissue-extraction lumen typically haveproblems with tissue clogging.

In another aspect of the invention, the negative pressure source 225coupled to the proximal end of tissue-extraction lumen 160 (see FIGS. 1and 4) also assists in aspirating and moving tissue strips 225 in theproximal direction to a collection reservoir (not shown) outside thehandle 142 of the device.

FIGS. 7A-7B illustrate the change in lumen diameter of cutting sleeve175 of FIG. 6B. FIG. 8 illustrates the distal end of a variation ofcutting sleeve 175′ which is configured with an electrode cuttingelement 195′ that is partially tubular in contrast to the previouslydescribed tubular electrode element 195 (FIGS. 5 and 6A). FIGS. 9A-9Bagain illustrate the change in cross-section of the tissue-extractionlumen between reduced cross-section region 190B′ and the increasedcross-section region 190A′ of the cutting sleeve 175′ of FIG. 8. Thus,the functionality remains the same whether the cutting electrode element195′ is tubular or partly tubular. In FIG. 8A, the ceramic collar 222′is shown, in one variation, as extending only partially around sleeve175 to cooperate with the radial angle of cutting electrode element195′. Further, the variation of FIG. 8 illustrates that the ceramiccollar 222′ has a larger outside diameter than insulative layer 202.Thus, friction may be reduced since the short axial length of theceramic collar 222′ interfaces and slides against the interfacinginsulative layer 200 about the inner surface of lumen 172 of outersleeve 170.

In general, one aspect of the invention comprises a tissue cutting andextracting device (FIGS. 10A-11C) that includes first and secondconcentric sleeves having an axis and wherein the second (inner) sleeve175 has an axially-extending tissue-extraction lumen therein, andwherein the second sleeve 175 is moveable between axially non-extendedand extended positions relative to a tissue-receiving window 176 infirst sleeve 170 to resect tissue, and wherein the tissue extractionlumen 160 has first and second cross-sections. The second sleeve 175 hasa distal end configured as a plasma electrode edge 180 to resect tissuedisposed in tissue-receiving window 176 of the first sleeve 170.Further, the distal end of the second sleeve, and more particularly, theelectrode edge 180 is configured for plasma ablation of a substantiallywide path in the tissue. In general, the tissue-extraction device isconfigured with a tissue extraction lumen 160 having a distal endportion with a reduced cross-section that is smaller than across-section of medial and proximal portions of the lumen 160.

In one aspect of the invention, referring to FIGS. 7A-7B and 9A-9B, thetissue-extraction lumen 160 has a reduced cross-sectional area in lumenregion 190A proximate the plasma cutting tip or electrode edge 180wherein said reduced cross section is less that 95%, 90%, 85% or 80%than the cross sectional area of medial and proximal portions 190B ofthe tissue-extraction lumen, and wherein the axial length of thetissue-extraction lumen is at least 10 cm, 20 cm, 30 cm or 40 cm. In oneembodiment of tissue-cutting device 100 for hysteroscopic fibroidcutting and extraction (FIG. 1), the shaft assembly 140 of thetissue-cutting device is 35 cm in length.

FIGS. 10A-10C illustrate the working end 145 of the tissue-cuttingdevice 100 with the reciprocating cutting sleeve or inner sleeve 175 inthree different axial positions relative to the tissue receiving window176 in outer sleeve 170. In FIG. 10A, the cutting sleeve 175 is shown ina retracted or non-extended position in which the sleeve 175 is at itproximal limit of motion and is prepared to advance distally to anextended position to thereby electrosurgically cut tissue positioned inand/or suctioned into in window 176. FIG. 10B shows the cutting sleeve175 moved and advanced distally to a partially advanced or medialposition relative to tissue cutting window 176. FIG. 10C illustrates thecutting sleeve 175 fully advanced and extended to the distal limit ofits motion wherein the plasma cutting electrode 180 has extended pastthe distal end 226 of tissue-receiving window 176 at which moment theresected tissue strip 225 in excised from tissue volume 220 and capturedin reduced cross-sectional lumen region 190A.

Now referring to FIGS. 10A-10C, FIGS. 11A-11C and FIGS. 12A-12C, anotheraspect of the invention comprises “tissue displacement” mechanismsprovided by multiple elements and processes to “displace” and movetissue strips 225 (FIG. 12A) in the proximal direction in lumen 160 ofcutting sleeve 175 to thus ensure that tissue does not clog the lumen ofthe inner sleeve 175. As can seen in FIG. 10A and the enlarged views ofFIGS. 11A-11C, one tissue displacement mechanism comprises a projectingelement 230 that extends proximally from distal tip 232 which is fixedlyattached to outer sleeve 170. The projecting element 230 extendsproximally along central axis 168 in a distal chamber 240 defined byouter sleeve 170 and distal tip 232. In one embodiment depicted in FIG.11A, the shaft-like projecting element 230, in a first functionalaspect, comprises a mechanical pusher that functions to push a capturedtissue strip 225 proximally from the small cross-section lumen 190B ofcutting sleeve 175 (FIG. 12A) as the cutting sleeve 175 moves to itsfully advanced or extended position.

In a second functional aspect, the chamber 240 in the distal end ofsleeve 170 is configured to capture a volume of saline distending fluid244 (FIG. 12A) from the working space, and wherein the existing RFelectrodes of the working end 145 are further configured to explosivelyvaporize the captured fluid 244 to generate proximally-directed forceson tissue strips 225 resected and disposed in lumen 160 of the cuttingsleeve 175 (FIGS. 12B and 12C). Both of these functional elements andprocesses (tissue displacement mechanisms) can apply a substantialmechanical force on the captured tissue strips 225 by means of theexplosive vaporization of liquid in chamber 240 and can function to movetissue strips 225 in the proximal direction in the tissue-extractionlumen 160. It has been found that using the combination of multiplefunctional elements and processes can virtually eliminate the potentialfor tissue clogging the tissue extraction lumen 160.

More particularly, FIGS. 12A-12C illustrate the functional aspects ofthe tissue displacement mechanisms and the subsequent explosivevaporization of fluid captured in chamber 240. In FIG. 12A, thereciprocating cutting sleeve 175 is shown in a medial position advancingdistally wherein plasma at the cutting electrode edge 180 is cutting atissue strip 225 that is disposed within lumen 160 of the cutting sleeve175. In FIG. 12A-12C, it can be seen that the system operates in firstand second electrosurgical modes corresponding to the reciprocation andaxial range of motion of cutting sleeve 175 relative to thetissue-receiving window 176. As used herein, the term “electrosurgicalmode” refers to which electrode of the two opposing polarity electrodesfunctions as an “active electrode” and which electrode functions as a“return electrode”. The terms “active electrode” and “return electrode”are used in accordance with convention in the art—wherein an activeelectrode has a smaller surface area than the return electrode whichthus focuses RF energy density about such an active electrode. In theworking end 145 of FIGS. 10A-11C, the cutting electrode element 195 andits cutting electrode edge 180 must comprise the active electrode tofocus energy about the electrode to generate the plasma for tissuecutting. Such a high-intensity, energetic plasma at the electrode edge180 is needed throughout stroke X indicated in FIG. 12A-12B to cuttissue. The first mode occurs over an axial length of travel of innercutting sleeve 175 as it crosses the tissue-receiving window 176, atwhich time the entire exterior surface of outer sleeve 170 comprises thereturn electrode indicated at 185. The electrical fields EF of the firstRF mode are indicated generally in FIG. 12A.

FIG. 12 B illustrates the moment in time at which the distal advancementor extension of inner cutting sleeve 175 entirely crosses thetissue-receiving window 176 (FIG. 12A). At this time, the electrodesleeve 195 and its electrode edge 180 are confined within the mostlyinsulated-wall chamber 240 defined by the outer sleeve 170 and distaltip 232. At this moment, the system is configured to switch to thesecond RF mode in which the electric fields EF switch from thosedescribed previously in the first RF mode. As can be seen in FIG. 12B,in this second mode, the limited interior surface area 250 (FIG. 12C) ofdistal tip 232 that interfaces chamber 240 functions as an activeelectrode and the distal end portion of cutting sleeve 175 exposed tochamber 240 acts as a return electrode. In this mode, very high energydensities occur about surface 250 and such a contained electric field EFcan explosively and instantly vaporize the fluid 244 captured in chamber240. The expansion of water vapor can be dramatic and can thus applytremendous mechanical forces and fluid pressure on the tissue strip 225to move the tissue strip in the proximal direction in the tissueextraction lumen 160. FIG. 12C illustrates such explosive or expansivevaporization of the distention fluid 244 captured in chamber 240 andfurther shows the tissue strip 225 being expelled in the proximaldirection the lumen 160 of inner cutting sleeve 175.

FIG. 14 shows the relative surface areas of the active and returnelectrodes at the extended range of motion of the cutting sleeve 175,again illustrating that the surface area of the non-insulated distal endsurface 250 is small compared to surface 255 of electrode sleeve whichcomprises the return electrode.

Still referring to FIGS. 12A-12C, it has been found that a single powersetting on the RF source 150 and controller 155 can be configured both(i) to create plasma at the electrode cutting edge 180 of electrodesleeve 195 to cut tissue in the first mode, and (ii) to explosivelyvaporize the captured distention fluid 244 in the second mode. Further,it has been found that the system can function with RF mode-switchingautomatically at suitable reciprocation rates ranging from 0.5 cyclesper second to 8 or 10 cycles per second. In bench testing, it has beenfound that the tissue-cutting device described above can cut and extracttissue at the rate of from 4 grams/min to 8 grams/min without anypotential for tissue strips 225 clogging the tissue-extraction lumen160. In these embodiments, the negative pressure source 125 also iscoupled to the tissue-extraction lumen 160 to assist in applying forcesfor tissue extraction.

Of particular interest, the fluid-capture chamber 240 defined by sleeve170 and distal tip 232 can be designed to have a selected volume,exposed electrode surface area, length and geometry to optimize theapplication of expelling forces to resected tissue strips 225. In oneembodiment, the diameter of the chamber is 3.175 mm and the length is5.0 mm which taking into account the projecting element 230, provided acaptured fluid volume of approximately 0.040 mL. In other variations,the captured fluid volume can range from 0.004 mL to 0.080 mL.

In one example, a chamber 240 with a captured liquid volume of 0.040 mLtogether with 100% conversion efficiency in and instantaneousvaporization would require 103 Joules to heat the liquid from roomtemperature to water vapor. In operation, since a Joule is a W*s, andthe system reciprocate at 3 Hz, the power required would be on the orderof 311 W for full, instantaneous conversion to water vapor. Acorresponding theoretical expansion of 1700× would occur in the phasetransition, which would results in up to 25,000 psi instantaneously(14.7 psi.times.1700), although due to losses in efficiency andnon-instantaneous expansion, the actual pressures would be much less. Inany event, the pressures are substantial and can apply significantexpelling forces to the captured tissue strips 225.

Referring to FIG. 12A, the interior chamber 240 can have an axial lengthfrom about 0.5 mm to 10 mm to capture a liquid volume ranging from about0.004 mL 0.01 mL. It can be understood in FIG. 12A, that the interiorwall of chamber 240 has an insulator layer 200 which thus limits theelectrode surface area 250 exposed to chamber 240. In one embodiment,the distal tip 232 is stainless steel and is welded to outer sleeve 170.The post element 248 is welded to tip 232 or machined as a featurethereof. The projecting element 230 in this embodiment is anon-conductive ceramic.

FIG. 13 shows the cross-section of the ceramic projecting element 230which may be fluted, and which in one embodiment has three fluteelements 260 and three corresponding axial grooves 262 in its surface.Any number of flutes, channels or the like is possible, for example fromtwo to about 20. The fluted design increases the availablecross-sectional area at the proximal end of the projecting element 230to push the tissue strip 225, while at the same time the three grooves262 permit the proximally-directed jetting of water vapor to impact thetissue exposed to the grooves 262. In one embodiment, the axial length D(FIG. 12A) of the projecting element 230 is configured to push tissueentirely out of the reduced cross-sectional region 190B of the electrodesleeve element 195. In another embodiment, the volume of the chamber 240is configured to capture liquid that when explosively vaporized provideda gas (water vapor) volume sufficient to expand into and occupy at leastthe volume defined by a 10% of the total length of extraction channel160 in the device, usually at least 20% of the extraction channel 160,often at least 40% of the extraction channel 160, sometimes at least 60%of the extraction channel 160, other times at least 80% of theextraction channel 160, and sometimes at least 100% of the extractionchannel 160.

As can be understood from FIGS. 12A to 12C, the distending fluid 244 inthe working space replenishes the captured fluid in chamber 240 as thecutting sleeve 175 moves in the proximal direction or towards itsnon-extended position. Thus, when the cutting sleeve 175 again moves inthe distal direction to cut tissue, the interior chamber 240 is filledwith fluid 244 which is then again contained and is then available forexplosive vaporization as described above when the cutting sleeve 175closes the tissue-receiving window 176. In another embodiment, a one-wayvalve can be provided in the distal tip 232 to draw fluid directly intointerior chamber 240 without the need for fluid to migrate throughwindow 176.

FIG. 15 illustrates another variation in which the active electrodesurface area 250′ in the second mode comprises a projecting element 230with conductive regions and non-conductive regions 260 which can havethe effect of distributing the focused RF energy delivery over aplurality of discrete regions each in contact with the captured fluid244. This configuration can more efficiently vaporize the captured fluidvolume in chamber 240. In one embodiment, the conductive regions 250′can comprise metal discs or washers on post 248. In other variation (notshown) the conductive regions 250′ can comprise holes, ports or pores ina ceramic material 260 fixed over an electrically conductive post 248.

In another embodiment, the RF source 150 and controller 155 can beprogrammed to modulate energy delivery parameters during stroke X andstroke Y in FIGS. 12A-12C to provide the optimal energy (i) for plasmacutting with electrode edge 180, and (ii) for explosively vaporizing thecaptured fluid in chamber 240.

FIGS. 16A-16C illustrate another embodiment RF cutting probe 700 withworking end 702 comprising a tubular cutter adapted for electrosurgicalcutting and extracting targeted tissue from the interior of a patient'sbody. However, in this embodiment, the inner cutting sleeve isconfigured to rotate instead of reciprocate as in thepreviously-described embodiments.

Referring to FIG. 16A, the outer sleeve 705 comprises a metal tubularmember 708 that extends from a handle (not shown) to a working end 702that again carries a distal dielectric body 710 defining a window 712therein. The inner second sleeve or cutting sleeve 715 comprises a metaltubular member 718 that carries a distal dielectric body 720 with awindowed side 724 that is adapted to cooperate with window 712 in theouter sleeve 705.

FIGS. 16B-16C show the working end 702 of probe 700 with the rotatingcutting sleeve 715 and RF electrode edge 725 in two different rotationalpositions with respect to outer sleeve 705 and window 712. In FIG. 16B,the inner sleeve 715 is rotated approximately 90° relative to the outersleeve 705. In FIG. 16C, the inner sleeve 715 is rotated 180° to aposition relative to inner sleeve 715 to effectively close the window712 defined by the outer sleeve 705. It can easily be understood howrotation of electrode edge 725 thus can cut tissue during rotation andcapture the tissue in the window-closed position within thetissue-receiving lumen 730 of the probe.

In this embodiment of FIGS. 16A-16C, the RF electrode edge 725 of theinner sleeve 715 comprises a first polarity electrode. The exteriorsurface 732 of the outer sleeve 705 comprises a second polarityelectrode as described in previous embodiments. As can be understoodfrom FIGS. 16A-16C, it is critical that the first and second polarityelectrode surfaces (725 and 732) are spaced apart by a predetermineddimension throughout the rotation of inner sleeve 715 relative to outersleeve 705. In one aspect the invention, the distal ends of the innerand outer sleeves comprise ceramic bodies 710 and 720 with an interface740 therebetween. In other words, the ceramic bodies 710 and 720 rotateabout interface 740 and the bodies provide exact electrode spacing ESbetween the first and second polarity electrodes 725 and 732.

Now referring to FIG. 17, it can be seen how the outer sleeve 705comprises as an assembly between the tubular metal sleeve 708 and thedielectric body 710, which in this variation can be a ceramic such aszirconium. In FIG. 17, it can be seen that the ceramic body 710 has athin wall 742 which can range in thickness from about 0.003″ and 0.010″wherein the ceramic extends 360° around window 712. Ceramic body 710 canthus be slidably inserted into and bonded to bore 728 in metal sleeve708.

Now turning to FIG. 18, the distal end of inner sleeve 715 is shownde-mated from the outer sleeve assembly 705 (see FIG. 16A). The tubularmetal sleeve 718 of FIG. 18 is fabricated to allow insertion of theceramic body 720 which supports the electrode edge 725 and provides arotational bearing surface about the interface 740 (see FIG. 16A). FIG.19 shows an exploded view of the inner sleeve assembly of FIG. 18. InFIG. 19, it can be seen that ceramic body 720 has a hemisphericalcross-sectional shape and includes an elongated slots 744 for receivingand supporting an electrode edge 725. FIG. 19 further shows metal sleeve718 without ceramic body 720 wherein the electrode edge 725 is cut froma rounded end sleeve 718. It can be understood that the slot 744 canreceive ceramic body 720 and thus the electrode edge 725 extends in aloop and under rotation will have a leading edge 745 and a trailing edge745′ depending on the direction of rotation. As used herein, the term‘leading edge’ refers to the electrode edge 725 extending around thedistal end of the sleeve 715 to its centerline on its rotational axis.

In one aspect of the invention, the tissue cutting probe 700 comprisesan outer sleeve 705 and an inner sleeve 715 that is rotatable to providewindow-open and window-closed positions and wherein the distal ends ofthe first and second sleeves 705, 715 include ceramic bodies 710, 720that provide surfaces on either side of a rotational interface 740.Further, the first and second sleeves provide ceramic bodies 710, 720that contact one another on either side of the rotational interface 740and thus provide a predetermined electrode spacing ES (FIG. 16A). In onevariation, the wall thickness of the ceramic body 710 is from 0.003″ to0.004″. Likewise, the wall thickness of ceramic body 720 can be from0.003″ to 0.004″. Thus, the radial dimension between the first andsecond polarity electrodes at a minimum in this variation is 0.006″. Inanother variation in which the inner sleeve 715 carries an outerpolymeric dielectric layer which can be 0.001″ in thickness to thusprovide an electrode spacing dimension ES of 0.004″. In other variationshaving a larger diameter, the dimension between the first and secondpolarity electrodes can range up to 0.030″. In general, the scope of theinvention includes providing a rotational tubular cutter with bi-polarelectrodes spaced apart between 0.004″ inches and 0.030″ inches whereinthe cutting sleeve 715 rotates about an interface 740 having dielectricmaterials on either side thereof.

In the embodiment shown in FIGS. 16A-16C, the length of the window canrange from about 5 mm to 30 mm. The diameter of the probe working endcan range from about 3 mm to 6 mm or more. The rotational speed of theinner sleeve can range from 100 rpm to 5,000 rpm. In one embodiment, arotation ranging from about 200 rpm to 500 rpm cut tissue efficientlyand allowed for effective tissue extraction as described below.

In another aspect of the invention, referring to FIGS. 17, 20A and 20B,it can be seen that an opening 748 is provided in ceramic body 710 whichprovides exposure through the ceramic body 701 to metal sleeve 708 whichcomprises the first polarity electrode when assembled. Thus, the metalsleeve provides an interior electrode surface 750 that is exposed tointerior chamber 730. It can be understood that in this variation, theworking end 702 can function in two RF modes as described in theprevious reciprocating probe embodiments (see FIGS. 12A-12C). In thefirst RF mode, the exterior surface 732 of outer sleeve 705 functions asa first polarity electrode in the interval when the inner sleeve 715 andits second polarity electrode edge 725 rotates from the window-openposition of FIG. 16A toward the window-closed position of FIG. 16B. FIG.20A depicts this interval of rotation, wherein it can be seen that thefirst RF mode operates for approximately 180° of rotation of the innercutting sleeve 715. In this position depicted in FIG. 20A, the leadingedge 745 and trailing edge 745′ of electrode edge 725 are exposed to theopen window 712 and electric fields EF extend to the first polarityelectrode surface 732 about the exterior of the probe and plasma isformed at leading electrode edge 745 to cut tissue.

The second RF mode is shown in FIG. 20B, wherein the inner sleeve 715rotates to the window-closed position and the probe switches instantlyto such a second RF mode since the electrode edge 725 is exposed only tothe tissue-receiving lumen 730. It can be understood that the second RFmode operates only when the window 712 is closed as in FIGS. 16C and 20Bwhich causes the instant explosive vaporization of captured saline inthe lumen 730. In FIG. 20B, it can be seen that the electrode edge 725is exposed only to the interior of lumen 730 and electric fields EFextend between the leading and trailing electrode edges (745 and 745′)to the exposed electrode surface 750 to thus cause the explosivevaporization of captured saline. The vaporization occurs instantlywithin limited degrees of rotation of the inner sleeve, e.g., 5° to 20°of rotation, upon closing the window 712 to thereby expel the resectedtissue in the proximal direction as described previously. It has beenfound that saline captured in the interior channel 730 can be distal tothe resected tissue or adjacent to the resected tissue in the lumen andthe fluid expansion in the liquid-to-vapor transition will instantlyexpel the resected tissue outwardly or proximally in lumen 730.

FIG. 21 is a longitudinal sectional view of the working end 702corresponding to FIG. 20B wherein the electrical fields EF are confinedwithin the interior lumen 730 to thus cause the explosive vaporizationof captured saline. Thus, the second RF mode and the vaporization ofcaptured saline 754 as depicted in FIG. 20B will expel the resectedtissue 755 proximally within the tissue extraction channel 730 thatextends proximally through the probe to a collection reservoir asdescribed in previous embodiments. In general, a method of the inventionincludes capturing a tissue volume in a closed distal portion of aninterior passageway of an elongate probe and causing a phase transitionin a fluid proximate to the captured tissue volume to expand the fluidto apply a proximally directed expelling force to the tissue volume. Thetime interval for providing a closed window to capture the tissue andfor causing the explosive vaporization can range from about 0.01 secondto 2 seconds. A negative pressure source also can be coupled to theproximal end of the extraction lumen as described previously.

Now turning to FIG. 22, another variation of inner sleeve 715′ is shown.In this embodiment, the leading edge 745 and the trailing edge 745′ ofelectrode edge 725 are provided with different electricalcharacteristics. In one variation, the leading edge 745 is a highlyconductive material suited for plasma ignition as described previously.In this same variation shown in FIG. 22, the trailing edge 745′comprises a different material which is less suited for plasmaformation, or entirely not suited for plasma formation. In one example,the trailing edge 745′ comprises a resistive material (e.g., a resistivesurface coating) wherein RF current ignites plasma about the leadingedge 745 but only resistively heats the trailing 745′ edge to thusprovide enhanced coagulation functionality. Thus, the leading edge 745cuts and the trailing edge 745′ is adapted to coagulate the just-cuttissue. In another variation, the trailing edge 745′ can be configuredwith a capacitive coating which again can be used for enhancing tissuecoagulation. In yet another embodiment, the trailing edge 745′ cancomprise a positive temperature coefficient of resistance (PTCR)material for coagulation functionality and further for preventing tissuesticking. In another variation, the trailing edge 745′ can have adielectric coating that prevents heating altogether so that the leadingedge 745 cut tissues and the trailing edge 745′ has no electrosurgicalfunctionality.

FIG. 23 illustrates another embodiment of inner sleeve component 718′ inwhich the electrode edge 725 has a leading edge 745 with edge featuresfor causing a variable plasma effect. In this embodiment, the projectingedges 760 of the leading edge 745 electrode will create higher energydensity plasma than the scalloped or recessed portions 762 which canresult to more efficient tissue cutting. In another embodiment, theelectrode surface area of the leading edge 745 and trailing edge 745′can differ, again for optimizing the leading edge 745 for plasma cuttingand the trailing edge 745′ for coagulation. In another embodiment, thetrailing edge 745′ can be configured for volumetric removal of tissue byplasma abrasion of the just-cut surface since it wiped across the tissuesurface. It has been found that a substantial amount of tissue (byweight) can be removed by this method wherein the tissue isdisintegrated and vaporized. In general, the leading edge 745 andtrailing edge 745′ can be dissimilar with each edge optimized for adifferent effect on tissue.

FIG. 24 illustrates another aspect of the invention that can be adaptedfor selective cutting or coagulating of targeted tissue. In thisvariation, a rotation control mechanism is provided to which can movethe inner sleeve 715 to provide the leading electrode edge 745 in anexposed position and further lock the leading edge 745 in such anexposed position. In this locked (non-rotating) position, the physiciancan activate the RF source and controller to ignite plasma along theexposed leading edge 745 and thereafter the physician can use theworking end as a plasma knife to cut tissue. In another variation, thephysician can activate the RF source and controller to provide differentRF parameters configured to coagulate tissue rather that to cut tissue.In one embodiment, a hand switch or foot switch can upon actuation moveand lock the inner sleeve in the position shown in FIG. 24 andthereafter actuate the RF source to deliver energy to tissue.

FIGS. 25 and 26 are schematic illustrations and block diagrams of oneembodiment of fluid management system 600 corresponding to the inventionthat is configured for hysteroscopic use with the probes as describedabove. As can be seen in FIG. 21, the hysteroscope 50 and tissue cuttingprobe 100 can deliver a cavity-distending fluid to the uterine cavity asdescribed previously. In one embodiment, the fluid management system 600includes a controller 605 that carries first, second and thirdperistaltic pumps 610A, 610B and 610C. The peristaltic pump can controlpressures throughout the system and provide predetermined flow ratesinto the uterine cavity and outward from the uterine cavity. Apredetermined flow rate and/or pressure can be used to distend theuterine cavity to thereby allow the physician to view tissue targetedfor treatment. Of particular interest, the system 600 as shown in FIGS.25 and 26 eliminates the need to weigh fluid volumes to determine fluiddeficit (and potential intravasation) which is found in prior artsystems. The fluid management system 600 in FIG. 25 comprisesfluid-in/fluid-out system in which a volume of fluid is recirculatedfrom a fluid source 620 into the uterine cavity and then outward fromthe uterine cavity into a filtering and sterilization subsystem 625.After the fluid is filtered and sterilized, it is returned to the fluidsource 620 which is typically a gravity-feed saline bag as illustratedin FIGS. 25 and 26.

In using the fluid management system 600 of FIG. 25, the physician onlyneeds to monitor the change in volume of fluid in the saline source orbag 620 to determine the fluid deficit. A cervical seal 630 is providedto prevent any substantial saline leakage outward from the uterinecavity around the hysteroscope 50. Similarly, the hysteroscope has aseal 630 in its working channel to prevent leakage around the shaft ofthe tissue cutting probe 100.

In one embodiment as shown in FIG. 25, the plurality of peristalticpumps 610A-610C are utilized to provide saline inflows into the uterinecavity as well comprising a negative pressure source (pump 610B) towithdraw saline and resected tissue from the uterine cavity.

As can be seen in FIG. 26, a first peristaltic pump 610A is configuredas a saline inflow pump and is positioned below the saline bag or source620. In one variation, a section of polyurethane tubing is engaged bythe peristaltic pump 610A which can consist of ⅜″ OD; ¼″ ID tubing.Other flexible inflow tubing 635 not engaged by peristaltic pump 610Acan consist of ¼″ OD ⅛″ ID tubing of PVC. A pressure sensor 638 isprovided downstream from the peristaltic pump 610A used for salineinfusion. The pressure sensor 638 is coupled to the controller 605 andcan pressure feedback signals can be used to modulate fluid inflows intothe uterine cavity.

Still referring to FIG. 26, it can be seen that pump 610B is configuredas a negative pressure pump mechanism to extract fluid and resectedtissue through flexible tubing 640, for example a ⅜″ OD; ¼″ ID tubingrating as a vacuum tubing. In FIG. 22, the second peristaltic pump 610Bor vacuum pump is provided to withdraw fluid from the probe 100 as wellas drive the fluid into a first tissue collection filter 650. In oneembodiment, the tissue collection filter 650 is a coarse filter that canhave any suitable form factor and can contain melt spun polypropylenefibers that provide a 1μ filtering pore size. In one example, the filter650 can be a McMaster Carr product having item number 5165K21 which hasa diameter of about 2.5″ and a length of about 9.75″. As can be seen inFIG. 26, resected tissue 652 is collected in the bottom of the filterassembly 650 for later collection for biopsy purposes.

The third peristaltic pump 610C comprises a high-pressure pump and isdownstream from the coarse filter 650. The high-pressure pump 610C isadapted to drive the coarsely filtered fluid through a molecular filter660 which is capable of removing all cells, blood constituents and thelike in the fluid flow. In one embodiment, the molecular filter 650 is aNephros DSU filter available from Nephros, Inc., 41 Grand Ave., RiverEdge, N.J. 07661. As can be further seen in FIG. 22, downstream from themolecular filter 660 is a return flow tubing 662 that returns thecleansed and sterilized fluid to the saline source or bag 620.

Of particular interest, molecular filter 660 is configured to allowre-infusion of a distending fluid into the patient. In effect, themolecular filter 660 is capable of cold sterilization of the saline orother fluid before it returned to the saline source or bag 620.

The pressure sensor 638 can be used to measure in-line pressures and canbe used to modulate the pressure inside the uterus via the controller.In one variation, the pressure sensor is air pressure sensor (convertedfrom the water pressure through a balloon within a pulse dampener) tomeasure and control the pressure inside the uterus. In anotherembodiment, the probe 100 or hysteroscope 50 can carry a pressure sensorfor measuring uterine cavity pressure and can be operatively connectedto the controller 605.

In another aspect of the invention, referring again to FIG. 25, a methodof use for cutting tissue from a targeted site in a space or potentialspace in a patient's body comprise utilizing the controller to modulateRF parameters in response to rates of fluid flow into an out of thespace in the patient's body. This aspect of the invention is enabled bythe fact that a single controller is provided (i) to control the RFcutting probe and (ii) to control the saline fluid inflows and outflow.More in particular, a method of the invention for cutting tissue in abody space comprises circulating a fluid though the space with a firstflow into the space and a second flow out of the space to thereby occupyor distend the space; actuating an RF probe to perform a cuttingprocedure at the site; and modulating an operating parameter of the RFprobe in response to a rate of the first or second flow.

Additional aspects of the method of cutting tissue include accessing thespace with an endoscope, providing a first flow of conductive fluid intothe space with the pump mechanism comprising a peristaltic pump. Asecond flow of fluid is provide to move fluid out of the space which isagain assisted by another peristaltic pump. The non-compliant aspects ofthe peristaltic pumps are important for controlling distending pressurein the body cavity, for example a uterine cavity. Further, the fact thatthe second flow through the probe varies depending on whether thecutting window is opened or closed and whether tissue contact issubstantial or insubstantial make it important to have the capability toadjust an RF parameter in response to inflows and outflow, or aderivative parameter such as intra-cavity pressure.

Thus, in the method described above, the operating parameter of the RFprobe can comprise RF power applied through the probe to tissue. Inanother embodiment, the operating parameter of the RF probe comprisesthe movement of an RF cutting component, which may be rotational speedof the RF cutting component, the speed of reciprocation of the RFcutting component, or axial-rotational oscillation of the RF cuttingcomponent. In another embodiment, the operating parameter of the RFprobe can comprise movement of a non-RF component of the working endsuch as a moveable outer or inner sleeve (or partial sleeve) or otherelement for cleaning tissue from the electrode surface. In anotherembodiment, the operating parameter of the RF probe can comprise a dutycycle or pulse rate of the applied RF energy or duty cycle of themovement of the RF cutting component.

In another aspect of the invention, an operating parameter of the RFprobe comprises a position of an RF cutting component relative to atissue-receiving window. Referring to FIG. 27, a method corresponding tothe invention comprises rotating the inner sleeve and stopping thesleeve in the maximum window-open position with the RF delivery off,applying suction to the central channel to suction tissue into thewindow, and then applying RF power to the bi-polar electrodes tocoagulate tissue stabilized and captured in and about the window.

The methods described above are applicable to any space or potentialspace in a patient's body and are particularly suited for fibroidremoval from a uterine cavity or removing tissue from within a joint.

In a fibroid treatment, the system utilizes a flow rate for salineinflows into the uterine cavity that ranges between about 100 ml/min and1,600 ml/min. In one embodiment, the fluid management system isconfigured to maintain a selected distending pressure it the uterinecavity by modulating only inflow rates provided by a first peristalticpump controlled by the controller, with a constant outflow rate providedby a second peristaltic pump, with controller algorithms responsive toRF probe parameters including: (i) the degree of window-open orwindow-closed positions which affects outflow volume; (ii) whether RFpower is ON or OFF, and (iii) the degree of tissue contact or engagementwith the window which can be measured by impedance or capacitive signalsfrom the bi-polar RF electrodes or other dedicated electrodes.

In another method of the invention for cutting tissue from a targetedsite in a uterine cavity, the measured or calculated pressure in thecavity can be used to modulate an operating parameter. In general, amethod comprises circulating a fluid though the space with a fluidinflow into the space and a fluid outflow from the space to therebyoccupy or distend the space, actuating an RF probe to perform a cuttingprocedure at the site and modulating an operating parameter of an RFprobe and/or the fluid management system in response to fluid pressurein the space. The operating parameter of the RF probe can be at leastone of the following: applied RF power, RF pulse rate, RF duty cycle,rotational and/or axial movement of an RF electrode component of theprobe, rotational and/or axial movement of a non-RF component of theprobe, fluid inflow into the space, or fluid outflow from the space.

Another method of treating tissue in a targeted site in a space in apatient's body, comprising the steps of positioning the working end ofan RF probe in the space, applying RF current to tissue from a moving RFelectrode to perform a cutting procedure at the site and applying RFcurrent to tissue from a non-moving RF electrode to perform acoagulation procedure at the site. The system and method includeproviding and utilizing a controller to selectively move or terminatemovement of the RF electrode cutting component. Thus, the probe suctionstissue into the window of the working end to permit the moving RFelectrode to cut tissue and optionally suctions tissue into the windowof the working end to permit the non-moving RF electrode to coagulatetissue.

It should be appreciated that while an RF source is suitable for causingexplosive vaporization of the captured fluid volume to expel or extracttissue as described above, any other energy source can be used and fallswithin the scope of the invention, such as an ultrasound transducer,HIFU, a laser or light energy source, a microwave or a resistive heatsource.

In another embodiment, the probe can be configured with a lumen incommunication with a remote liquid source to deliver fluid to theinterior chamber 240.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

What is claimed:
 1. A system for treating tissue in a targeted site in a space in a patient's body, comprising: a tissue resecting device including: an outer sleeve having a lumen; and an inner sleeve movably positioned in the lumen of the outer sleeve, the inner sleeve including a tissue extraction lumen; wherein the inner sleeve comprises a first polarity electrode and the outer sleeve comprises a second polarity electrode; a controller including a radio frequency generator for applying RF current between the first and second polarity electrodes; wherein the controller is configured to apply RF current to tissue from the first polarity electrode to perform a resection procedure at the site while the first polarity electrode is moving relative to the outer sleeve; and wherein the controller is configured to apply RF current to tissue from the first polarity electrode to perform a coagulation procedure at the site when the first polarity electrode is not moving relative to the outer sleeve.
 2. The system of claim 1, wherein the controller is configured to selectively move or terminate movement of the first polarity electrode.
 3. The system of claim 1, further comprising: a fluid management system configured to circulate a conductive fluid though the space.
 4. The system of claim 3, wherein the fluid management system is configured to extract the conductive fluid and resected tissue through the extraction lumen from the space.
 5. The system of claim 1, wherein the outer sleeve includes a side window and the first polarity electrode moves across the side window when the first polarity electrode is moving relative to the outer sleeve.
 6. The system of claim 5, wherein the first polarity electrode is exposed through the side window when the first polarity electrode is not moving relative to the outer sleeve.
 7. The system of claim 6, wherein the controller is configured to lock the first polarity electrode in an exposed position with the first polarity electrode exposed through the side window.
 8. The system of claim 5, further comprising means for suctioning tissue into the side window of the outer sleeve to permit the moving first polarity electrode to resect tissue.
 9. The system of claim 8, wherein the first polarity electrode reciprocates across the side window during the resection procedure.
 10. The system of claim 1, wherein the controller is configured to selectively move or terminate movement of the first polarity electrode.
 11. A system for resecting tissue, comprising: a tissue resection device including an outer sleeve having a side window and an inner sleeve movably positioned in the outer sleeve, wherein a distal end of the inner sleeve comprises a first polarity electrode with a distal electrode edge configured to move across the side window, and the outer sleeve comprises a second polarity electrode; a fluid management system for circulating a fluid through a space in a patient's body with a first flow into the space and a second flow out of the space to thereby occupy or distend the space; and a controller for applying RF current to the first polarity electrode to resect tissue extending into the side window while the first polarity electrode is moving relative to the outer sleeve and coagulate tissue when the first polarity electrode is not moving relative to the outer sleeve.
 12. The system of claim 11, wherein the first polarity electrode moves across the side window when the first polarity electrode is moving relative to the outer sleeve and the first polarity electrode is exposed through the side window when the first polarity electrode is not moving relative to the outer sleeve.
 13. The system of claim 12, wherein the controller is configured to lock the first polarity electrode in an exposed position with the first polarity electrode exposed through the side window.
 14. The system of claim 11, wherein the fluid management system includes a saline source having a volume of less than 3 liters.
 15. The system of claim 14, wherein the fluid management system is configured to recirculate the fluid from the space back to the saline source.
 16. The system of claim 11, wherein the second polarity electrode comprises an exposed surface of the outer sleeve, and wherein an electrode surface of the second polarity electrode has a larger surface area compared to the functionally exposed surface area of the distal cutting electrode edge.
 17. The system of claim 11, further comprising an endoscope including a working channel and a fluid inflow channel, wherein the tissue resection device is configured to extend through the working channel.
 18. The system of claim 17, wherein the fluid management system is configured to circulate the first flow of the fluid into the space through the fluid inflow channel.
 19. The system of claim 18, wherein the fluid management system is configured to circulate the second flow of the fluid out of the space through an extraction lumen of the inner sleeve.
 20. The system of claim 19, wherein the fluid management system is configured to recirculate the fluid from the space back to a saline source of the fluid management system. 